I think the Original trilogy for the most part is very good film making especially considering the limits imposed when making 1970's or 1980's sci fi of all things but there are things I would like to have seen. These scenes include :

Luke flying his T-16 Skyhopper shooting Womp Rats on Tatooine
The Imperials arriving on Bespin Cloud city
Lando infiltrating Jabba's Palace
Jabba's sail Barge and skiffs leaving the Palace for the Great Pit of Carkoon
and a closer scene of the Endor Death Star II shield generator dish installation with Imperial Personnel.

None of these are essential to the movies but it would have been nice to see them in any case. What extra scenes would you have liked to see in the Trilogy ?

I would have liked to have seen better development of Han Solo´s character. In principle it was adequate, but compared to the ones of the sequel trilogy, it wasn´t very inspiring. He needed more depth.

I fought on the battlefield. I retired to embrace a life of discovery and profit. I carve my own path in life and am better for it.